When goldfish breed, the male fish drives the female into soft plants so that when the eggs are laid, they get stuck in the plants and they can develop safely. Rather than using live plants all the time, many breeders simulate plants by making what are called spawning mops. These are handy because they can be easily removed to a fry grow-out tank when spawning is finished, and they can be sterilized after use, unlike live plants. This guide will show you a cheap and easy way to make your own spawning mops.
You'll need some acrylic yarn in any color you'd like. But just keep in mind two things; first, eggs will be much easier to see on a darker color, and second, some people think that fish breed more readily on green yarn since it looks like real plants. You'll also need scissors, tape, some cork bottle stoppers, and a hardcover book. The book should be almost as tall as the aquarium you're going to use the mops in.
Cut off a length of yarn and lay it horizontally across the book. Use a couple pieces of tape to hold it in place while you work.
Begin winding the yarn vertically around the book. Go around about 100 times. You can do fewer or more times depending on how thick you want your mop to be.
Move the horizontal piece of yarn up to the top of the book, and use it to tie a knot at the top.
Take your scissors and cut the yarn at the bottom of the book.
Take a cork, place it in the middle of your mop (where the knot is) and fold the mop in half to completely cover the cork. Then, while holding the top tight with one hand, tie a length of yarn around it to keep the cork held securely in place.
Boil some water in a large pot. Once it has reached a rolling boil, remove the pot from heat and soak your spawning mop in the hot water for about 15 minutes. Do not leave the pot on the heat while the spawning mop is soaking, because the boiling water will tangle the threads of the mop and it will be difficult to fix. I found this out the hard way. :/ After it has soaked, rinse it off in cool water, and it's ready to use!
Even my cat, Sami, approves!
If you prefer a video demonstration, feel free to check out the video version of this guide as well!